The American Association of Equine Practitioners (AAEP) has published comprehensive guidelines for the identification, treatment and prevention of pigeon fever (Corynebacterium pseudotuberculosis infection), traditionally among the most common infectious diseases in horses in the western United States. During the last decade, disease incidence has increased considerably in other regions, including the midwest.

The guidelines, available online, summarize the clinical signs, diagnostic methods for various clinical forms of the disease, treatments, and approaches to biosecurity and control. They also offer new insights into the use of serologic testing—with links to laboratories offering such testing—and antimicrobial therapy for internal infection.

Infection in horses is caused by the C. pseudotuberculosis bacterial organism, which thrives in hot dry weather. The organism can survive for up to two months in hay and shavings, but new research has found that it can survive for more than eight months in soil contaminated with manure, placing increased emphasis on good sanitation practices.

The portal of entry for the bacteria is through abrasions or wounds in the skin or mucous membranes or through inhalation. Pigeon fever expresses itself most often as external abscesses in the pectoral (chest) or ventral (lower) abdomen, and less frequently as internal infection or ulcerative lymphangitis